Centrifugal hammer



Sept 26, 1933. L. w. VAN BUSKIRK CENTRIFUGAL HAMMER Filed Nov, 6, 1931Patented Sept. 26, 19.33 A;

1,928,516 onnrarrooaa HAMMER Lesher Wharton Van Buslrirk, Easton, Pa.

Application November 6, 1931. Serial No. 573,506

' 4 Claims. (Cl. Sis-11) The present invention relates to new anduseful' improvements in centrifugal hammers such as used in machines forpulverizing or crushing coal, stone, and other materials, and theprimary object of the invention is the provision of a novel and improvedbreaking, pulverizing or crushing hammer or member for use in a rotaryor'centrifugal disintegrator which will be both economical and efiicientin operation.

Another object of the invention is the provision of a hammer which has aremovable and replaceable head or wear end which may be readily replacedby a new one when worn out.

A furtherobject of the invention is the provision of a centrifugal orsimilar hammer having a replaceable head whichmay be reversed so as topresent a new sharp crushing or pulverizing surface to the materialworked upon.

A further object is the provision of a novel hammer or crushing memberof the kind indicated wherein when the forwardly presented crushingfaces have beenreversed and worn out, the renewable head can be reversedend for end and the faces thus presented can be reversed when worn untilboth faces are worn out; thus, the removable crushing member is adaptedto present four sharp crushing surfaces before being renderedunserviceable for further use.

I A further object is the provision of a hammer or crushing member ofthe kind indicated wherein the crushing faces disposed at the oppositesides of the hammer have a depressed area be-- tween the faces and thisdepression is of such shape that after one crushing face has worn a newcrushing face will be presented without requiring the reversal orturning end to end of the crushing member. Thus, a hammer having areplaceable head of this type when originally put into service with foursharp crushing surfaces will develop into a head. progressivelypresenting.

eight crushing surfaces before the head is Worn out and replaced.

A further object is the provision of a hammer of the type indicatedwherein, when the. removable head is worn out, there will be a minimumamount of metal remaining in the head, thereby reducing the waste ofmetal. 1 r

A still further object of the invention is to pro vide a two part hammerin which the. renewable head is retained rigidly on the shankWithout'the" use of bolts, pins or similarfastening elements.

With the foregoing obiectsin view the invention will be betterunderstood by reference to the following description when read inconnection with the accompanying drawing illustrating the preferredembodiment thereof, and in which,

Fig. 1 is a side elevation of the improved centrifugal hammer.

Fig. 2 is an end view of the hammer.

Fig. 3 is a fragmentary detail perspective View of the parts of thehammer.

Fig. 4 illustrates the manner in which one prong of the crushingorpulverizing head progressively wears away to present a new crushing faceafter the original crushing face has worn out.

Fig. 5 shows a crushing head turned end to end to present a new crushingface after the one of the prongs has worn out.

The numeral 1 designates a flat bar metal shank having a hole 2 at oneend for pivotal mounting in a rotor, as usual in this form of hammer.The outer extremity of the shankis enlarged in cross section, suchenlargement be ing greater than the cross section of the apertured end 8so that the hammer head 4 can be assembled with the shank by slipping itover the head end thereof. The enlarged portion 5 of the shank a fitssnugly within the opening 6 of the head and terminates in outwardlybeveled portions 7 fitting snugly within corresponding beveled recesses8 so as to insure that the enlarged end of the shankv is wedged intothe" head. The renewable head is symmetrical about both of its centerlines in order to be reversible to different positions so as tosuccessively present new'crushing faces beforethe head is replaced.

It will therefore be noted that the symmetrical beveled recesses 8disposed toward the apertured end of the shank will have the effect ofdecreasing the bearing or support of the head on the shank. Therefore,in order to increase the support and securely retain the head inposition on the shank, a wedge shaped collar 9 with extensions 21 oneach sidereceived in grooves 22 in the head, is formed with alongitudinal groove or channel 10 to straddle the shank and with beveledextensions 11 to match the beveled recesses 8 in the head. The collarand the shank are provided with registering apertures 13 and it for thereception of a fastening element 15 for securely retaining the partstogether in assembled relation.

It is sometimes desirable to have the head of the centrifugal hammerarranged so that it is "retained in unsymmetrical relaticnor cooked withrespect to the center line of the shank." This may be accomplished byforming the beveled ends '7 and corresponding beveled recesses. 8 withdifierent inclinations. V

In use, the cutting edges or grinding faces 16 of the head are graduallyworn away and dulled and the ends thereof assume a convex shape, asindicated at 17 in Fig. 4. The head may then be removed from the shankand reversed and secured in adjusted position by the wedge 9 andfastening element 15 so as to present a new and sharp cutting edge.

An important feature of the invention is the provision of a grindinghead provided with prongs each having two grinding faces such that, whenone face has become worn, the other face is presented to they material.This is accomplished by forming the head with depressions or channelshaving inclined side edges 18. The pronged extensions thus formedpresent grinding faces 16 which, when worn, as indicated at 19 in Fig.4, merge into the other grinding face 18. It will therefore be apparentthat the particular shaped prongs, instead of having one grindingsurface which, when dulled, requires the removal of the head, presentstwo grinding surfaces to be dulled before requiring the head to bereversed on the shank to present a new prong to the material, asindicated by the numeral 20 in Figs. 1 and 5. Thus, a replaceable headhaving four prongs will successively present eight cutting faces beforebeing worn out and replaced.

From the above description it will be apparent that I have provided arigid centrifugal hammer in which the wear of the hammer head is doubleat the grinding or contact faces of each prong before requiring reversalon the shank to present a new grinding surface, thus materiallyprolonging the average period of use of the hammer head beforereplacement thereof arises.

Having thus described my invention, what I claim is:

1. A hammer of the character described comprising a shank having one endadapted to be pivotally mounted, the other end of the shank beingenlarged in cross section and having 0ppositely disposed beveledextensions, and a reversiblegrinding head having an opening for the headto slip over the first mentioned end of the shank, said head havingbeveled recesses merging into the opposite ends of the opening toreversibly receive the beveled extensions to retain the head in positionagainst centrifugal force, a collar embracing the shank and having apair of beveled extensions extending into corresponding beveled recessesin the head, and means for securing said collar to the shank.

2. A hammer of the character described comprising a shank having anenlarged end adapted to be pivotally mounted, the other end of the shankbeing enlarged in cross section to a greater extent than the other endand having laterally extending beveled extensions, and a reversiblegrinding head having an opening for the head to slip over the firstmentioned end of the shank, said head having beveled recesses merginginto opposite ends of the opening to reversibly receive the beveledextensions to retain the head in position against centrifugal force, anapertured collar embracing the second mentioned enlarged end of theshank from one end thereof, said collar having a pair of beveledextensions received in corresponding beveled recesses in the head, andmeans for securing the collar to the shank.

3. A hammer of the character described, coinrising a shank having oneend adapted to he pivotally mounted, the other end of the shank beingenlarged in cross section and having a seat portion, a reversiblegrinding head having an opening for the head to slip over the firstmentioned end of the shank, said head having seat providing meansadjacent the opposite ends of the opening to reversibly receive the seatportion of the shank to retain the head in position against centrifugalforce, and removable supporting means positionable on the shank andadapted to supportingly engage the seat providing means of the head,which is not engaging the seat portion of shank, whereby to support andsustain the same.

4. As a new article of manufacture, a hammer head having means fortransverse seating on a shank, said head providing primary grindingportions at each end, selectively engageable with the material to beground according to the position of the head on the shank, and each endof said head having a recess diverging to greater width in the directionof the outer adjacent end of the head, whereby to separate and space theprimary grinding portions, and said outwardly diverging walls of saidrecess at each end of the hannner providing a pair of secondary grindingedges adapted to be presented for service when the corresponding primarygrinding edges have been worn down.

LESHER WHARTON VAN BUSKIRK.

